Advances in communications systems and protocols have resulted in wide scale deployment of devices and networks having different technologies. A myriad of network service providers implement solutions that are customized and designed to take advantage of or promote features which may be inherent or unique to their network infrastructure. The demand for services by end users and the competition among providers, along with the rush to make services available to end users, superseded any cohesive effort by providers to implement a robust architecture. In general, there have been advancements in the type and nature of end user devices that are utilized by individuals and businesses alike. End user devices are blurring any distinctions that may have existed between data, speech and mobile technology. The desire and trend today is for real time, multi-media services which includes voice, video telephony, messaging, conferencing and push-to-talk services. To address this need, new mobile network infrastructures have been developed and adopted to allow the convergence of data, speech and mobile technology over an Internet Protocol (IP) based infrastructure. Importantly, these networks have been developed by multiple service providers. Nonetheless, users expect to be able to communicate with one another irrespective of the network that is serving them or other users.
Substantial investments have been made in legacy communication systems. It is impractical and extremely cost prohibitive for service providers to replace their infrastructures and systems to adopt any new architecture, regardless of how robust the newly introduced technology may be. It is also not economical, practical or efficient to re-invent services or functions for a new system, when they already exist on the legacy systems. As such, it is necessary to have a means for new architectures to interact or be integrated with legacy systems, so as to provide access to select legacy services or functions.
Recently for example, there has been some integration of wireless and landline network infrastructures. This integration has resulted in some additional services and functions for end users of the wireless and landline networks. One of the new services is the Push-to-talk (PTT) service. This service is also commonly referred to as Push-to-talk over cellular (PoC). In operation, PTT provides a one-to-one or one-to-many communication service in a mobile network. The communication connection is operatively half-duplex and is generally initiated by the push of a button on a client device, in a similar fashion to a walkie-talkie. Call connection with PTT service is generally less resource intensive than circuit-switched cellular services because resources are only tied up in one direction, for the duration of a caller's comment burst, rather than an entire call session. However, PTT lacks certain services which are available on other mobile networks and landline networks.
User demands for features and connectivity to other networks and devices led to the development of an industry protocol. The protocol, known as Session Initiation Protocol (SIP), provides the flexibility to use and control common technologies in enterprise networks. SIP is essentially a protocol for providing control or signaling that is used for establishing, modifying and terminating sessions in which there are one or more participating devices. SIP runs over different transport protocols and is independent of the media transport. A SIP session is created by an invitation from a calling device to a recipient device. The invitation carries session descriptions that allow intended participants to agree upon a set of compatible media types. A session may include Internet telephone calls e.g. Voice over IP (VoIP), voice calls, video calls, multi-media distribution, Instant Messaging (IM), teleconferencing or presence detection. SIP utilizes proxy servers to route invitations, identify a user's location, provide authentication for access to services, and implement provider routing policies, among other things. SIP is a widely accepted protocol by legacy land line providers for introducing services within the enterprise and providing services to mobile carriers.
PTT is a platform that can provide support for many functions and services beyond the traditional spontaneous voice communication. In order to provide additional functions and services in a complete and robust manner, it is necessary to have connectivity and continuity between wireless communications systems and land line communications systems such as the Internet or public switched Telephone Network (PSTN). Current platforms and architectures do not support certain services and certainly do not utilize the full extent of the communication resources that are implicated during PTT sessions or PTT service provisioning.
Accordingly, there exists a need for a manner of providing services from legacy networks to PTT devices. Even further, there is a need for providing services without additional overhead or resources. Further still, there is a need to utilize the unused portions of a communication bandwidth during a PTT session, to enable the provision of additional services and information that would further enhance the end user experience.